How do I return values from one class to another?

Question

I just need to return a value which is the savings value back to the call method on the main class. I extended the sub class but it doesn't work. I also tried importing the sub class into the parent class as an object, still no success.

package package1;

import java.util.Scanner;

public class GnX {
   FvX fvx = new FvX( );    
         
   public static void main(String[] args) {
        double price;
        double discount;
        double savings;
        Scanner scan = new Scanner(System.in);  
        
        
        System.out.println("Enter a base price for the discount: ");
        price = scan.nextDouble( );
        System.out.println("Now, Enter a discount rate: ");
        discount = scan.nextDouble( );
    
        displayInfo( );
        computeDiscountInfo( );
    
        System.out.println("Special this week on any service over " + price);
        System.out.println("Discount of " + discount);
        System.out.println("That's a savings of at least $" + savings);
    }

    public static void displayInfo( ) {
        System.out.println("Paradise Guitar Is A Fantastic Place To Reherse"); 
        System.out.println("This Rehersal Room Is Studio Based");
    }
}

Class that's inherited through parent class in a separate window:

package package1;

public class FvX extends GnX {

    public FvX( ) {
    }
    
    public static double computeDiscountInfo(double price, double discount) {
        double savings;
        savings = price * discount / 100;
        return savings;
    }
}

Answer 1

Assuming you are wanting to use computeDiscountInfo. This belong to the fvx object so it should be called as fvx.computeDiscountInfo(...)

Now consider

1. it returns a double, so you can do double rv = fvx.computeDiscountInfo(...)
2. you notice that I have wrote (...), because this method takes a couple of paramaters double price, double discount. so you should call using the parameters instead of ... maybe double rv = fvx.computeDiscountInfo(price, discount);